Antihalation film



Nov. 9, 1943. G F NAEAU ETA- 2,333,809

' ANTIHALATION FILM VFiled Oct. 18, 1941 n :Mama/v xwwzm a ,o xm caw/.05E im? SUPPORT ,2 ///z ,3 ANr/HAzAr/aw Arf/e conm/wma WATER-Mmmm: cm1/0:5 fsm?,

- su/rfArf-Arr/vf /m LIGHT-Awww@ mmm:

.FIG 2 5w: .sf/vs/r-/vf LA YER 14 gmmm GREEN .sens/wv@ Arf/r l5 mi@ RED sENs/r/vs LAYER 6 ceuumsf ESTER .suf/mr '0 sues/Na LAYER @LE ARNADEAU v D. LACK CLARK J. SMITH ATfoRNYs Patentes Nov. e, i

UNiT-s saires NT4 GFF@ ANrrsrroN FILM Gale F. Nadeau, Alfred D. Slack. and Clark J. Smith, Rochester, N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application October 18, 1941, Serial No. 415,590

7 Claims.

Serial No. 381,694, illed March 4, 1941, now Patentl No. 2,289,799, of July 14, 1942.

Light-absorbing coatings on the backs of photographic iilms are well known in the art of halation prevention. Generally, these antihalation coatings consist of a carrier material and a light. absorbing material such as a 4dye or pigment, and are removable or non-removable according to the solubility characteristics of the carrier material. The coatings Iare applied, as a rule, to the rear side of a lm support which may be a cellulosel ester, a synthetic resin, or other material. ff Coatings on the backs of lms containing a dye or a superficial dye layer removable in photographic processing solutions are well known for antihalation purposes. Less well known are antihalaticn layers which are designed to be nonremovable in aqueous or alkaline photographic processing solutions. The disadvantages of the removable types of coatings are the tendency of some coatings to deposit sludge in processing solutions, the tacky nature of some coatings, the known thermo-plastic qualities of other coatings which are in general undesirable, and vfurthermore, in the case of certain resinous coatings their tendency to form insoluble products with the antlhalation dye. Non-removable antihalation layers have been designed to avoid the dimculties and to a certain extent prevent the penetration of the dye into and the subsequent staining of the support. 'I'he success of this practice depends upon the selection of a material, for the dye carrier, which is suiilciently permeable to processing solutions, yet not soluble, that the dye giving antihalaticn protection may be completely discharged when desired.

1 In previous patents surface-,active materials for facilitating the removal of hydrophilic backings have been disclosed. These backings in general consist of an alkali or water soluble material such as cellulose acetate phthalate as the carrier material for the dye, and the known property of the dye to stain the base is controlled bythe thickness of the cellulose acetate phthalate layer. In other words. a given thickness of cellulose acetate phthalate was found to vbe required for a xed density of dye to be appliedto the support. If for another purpose the dyedensity was to be increased, it was found necessary to increase the thickness ofthe backing layer. In other words, the backing acted as-a sort of mordant for the dye and prevented it striking into the permanent support. Once the dye has penetrated the permanent support, it is not removable by any photographic processing treatment.

WeA have found in the course of investigating that it is' posvarious surface-active materials, sible to control the degree of base stain by the use of these materials. This is of special importance in connection with the design of waterpermeable but non-removable antihalation backing layers. A backing of this type offers distinct advantages over a removable backing in that materials possessing lesser water-susceptibility may be used'. This fact is important in determining the ferrotyping tendency of the iilm.

For some time it has been possible to make a 111m using, for example, a cellulose acetate of low acetyl as a carrier for an antihalation dye, as disclosed in Nadeau and Slack U. S. Patent 2,311,073, granted February 16, 1943. There has been in this instance, however, denite residual stain which, although not particularly objectionable in the case of black-and-white film, is serious in a case of a ilm used for carrying a colored image. A more detailed investigation of the properties of various surface-active materials has shown that this residual stain can be controlled by adding surface-active agents to the antihalation backing layer.` Of the known types of surface-active agents, all are active in the prevention of base stain, whether of the anionic, cationic or non-ionic type.

The object of the present invention, is therefore, to provide 'photographic lms with antihalation backlngs of water-permeable cellulose esters containing a surface-active agent and a light-absorbing material, the surface-active agent cooperating with the carrier material to prevent base stain.

This object is accomplished by the methods, examples, and materials hereinafter described.

lSurface-active agents representative oi' the anionic type useful in the backlngs of our invention, are the commercial products, Arctic Syntex T, Igepon T, (alkyl sodium taurides) 'etc., described in thepprior U. S. Patent No. 2,139,778 for usein static prevention. Other agents of this type are sodium alkyl sulfates, such as Gardinol, and sodium sulpho di-alkyl succinates such as Aerosol AY (sodium sulpho di-amyl succinate) and Aerosol OT (sodium sulpho-di-octyl succinate).`

Surface-active agents of the cationic type are Aunderstood that these examples represent the preferred embodiment, but are not to be considered as limiting our invention thereto.

Example 1 An vantihalation backing can be prepared by applying the following solution of cellulose acetate phthalate to a support such as cellulose acetate propionate or cellulose nitrate:

Per cent Cellulose acetate phthalate (23% acetyl, 13%

phthalyl) 13 Water--- 17 Methyl Cellosolve 26 Ethanol 44 To the above formula is added a surface-active agent such as Aerosol AY, in the amount of from about 1 per cent to about 5 per cent of the weight of the solution. Over this layer is applied a dye solution containing a dye such as Acid Blue 3R, or other fugitive dye, in suitable amounts to obtain the desired density in the backing layer, from a solvent combination consisting of 90 per cent methyl alcohol and per cent water. Ii desired the surface-active agent may be applied in the dye solution instead of in the carrier coating solution.

Emamplez A cellulose acetate propionate lm support may be coated with a solution of the following composition:

Per cent Cellulose acetate (34% acetyl) Methyl Cellosolve Ethylene dichloride 30- Methyl alcohol 33 Acetone v15 To this formula may be added a surface-active agent such as Arctic Syntex T to the extent of about 1 per cent to about 5 per cent of the weight of the solution. The layer can be dyed by the same dye formula mentioned in the previous example. l

Example 3 A film base may be coated with a solution of the composition shown in Example 2 except that a more extensively hydrolyzed cellulose ester, such as cellulose acetate propionate (15.9 per cent acetyl and 5.3 per cent propionyl) may be used instead of cellulose acetate. The dye solution of Example 1 may also be used for coloring this layer.

As carrier materials in the antihalation backing layers prepared in the manner of our invention, other water-permeable but water-insoluble cellulose organic acid esters may be used, such as those disclosed in Nadeau and Slack U. S. Patents 2,289,799, granted July 14, 1942 and 2,311,073, granted February 16, 1943. The technique described therein for obtaining adequate adhesion between the autihalation layers and supports of well esteriiied cellulose organic acid and mixed emulsion layers.

organic acid esters, may be used in the present invention for eifecting adhesion between waterswellable carriers containing a surface-active agent and a light-absorbing material, and said supports. As light-absorbing materials, fugitive dyes and mixtures of fugitive dyes, are suitable.

The iigures of the accompanyingv drawing shows in cross-sectional view two sensitive photographic lms provided with the antihalation layer of the invention.

In the drawing accompanying this application, Fig. 1 shows 4a cellulose ester lm support I0,

carrying an emulsion layer II on one side, and on v adhesively joined to the support by meansof a subbing layer I2.

A color ilm constructed in this general manner may contain intermediate lter and masking The emulsions may also contain color-forming compounds developable to colored images in a known manner, or may be sensitized to different regions of the spec'- trum and be4 colored complementary to their sensitivity for the production of colored images by well-known bleach-out processes. Films carrying emulsion layers of these types are disclosed y in the prior patent Mannes and Godowsky U. S.

2,252,718, granted August 19,1941, Ehrenfried U. S. Patent 2,322,001, granted June 15, 1943, and Jelley and Vittum U. S. patent application 371,612, flied December 26, 1940.

It is to be understood that the disclosure herein is by way of example and that we consider as included in our invention all modications and equivalents falling within the scope of the appended claims.

What we claim is:

1. A photographic film comprising a cellulose ester support having on one side thereof a lightsensitive emulsion layer, and on the opposite side,

an antihalation layer of a cellulose organic acid' ester permeable -but not soluble in photographic processing solutions. containing av surface-active agent anda light-absorbing material.

2. A photographic film comprising a cellulose ester support having on one side thereof a lightsensitive emulsion layer, and on the opposite side an antihalation layer of a cellulose organic acid ester permeable but not soluble in photographic processing solutions, containing an anion surface-active'agent and a light-absorbing material. 3. A photographic film comprising a cellulosel ester support having on one side thereof a lightsensitive emulsion layer, and on the opposite side an antihalation layer of a cellulose organic acid ester permeable but not soluble in a photographic developing solution, containing sodium sulpho di-arnyl succinate and a. light-absorbing material.

4. A photographic nlm comprising a cellulose ester support having on one side thereof a lightsensitive emulsion layer, and on the opposite side an antihalation layer of a cellulose organic acid ester permeable but lnot soluble in photographic processing solutions, containing a cation surfaceactive agent and a light-absorbing material.

5. A photographic film comprising a cellulose ester support having on one side thereof a lightsensitive emulsion layer, and on the opposite side an antlhalation layer of a cellulose organic acid ester permeable but not soluble in photographic processing solutions, containing dimethyl cetyl benzyl ammonium chloride and a light-absorbing material.

6. A photographic lm con'mrisingl a cellulose ester support having on one side thereof a lightacid ester permeable but not soluble in photographic processing solutions, containing a nonion surface-active agent and a light-absorbing material. 4

7.A photographic iilm comprising a, cellulose ester support having on one side thereof 'a lightsensitive emulsion'layer, and on the opposite side an antihalation layer of a cellulose organic acid ester permeable but not soluble in a photographic developing solution, containing an ether of polyethylene glycol and a light-absorbing material.

" GALE F. NADEAU.

ALFRED D. SLACK. n CLARK J. SMITH. 

